53
53
SHOW SESSION STATUS LIKE 'Last_query_cost';
56
56
EXPLAIN SELECT a FROM t1;
57
57
id select_type table type possible_keys key key_len ref rows Extra
58
58
1 SIMPLE t1 ALL NULL NULL NULL NULL #
59
59
SHOW SESSION STATUS LIKE 'Last_query_cost';
62
62
SELECT a FROM t1 UNION SELECT a FROM t1 ORDER BY a;